As noted in application Ser. No. 488,773, many large industrial enterprises, particularly fresh-water-cooled thermal-power stations, require the supply and disposal of large but regulated quantities of water, especially for cooling purposes.
When water is to be drawn from a natural water supply (e.g. a lake or stream), the control system must be able to take into account:
A. fluctuating requirements of the load; PA1 B. fluctuations in water level of the source; and PA1 C. possible breakdown of intake machinery and filters.
In addition, the system must provide water of substantially constant temperature, must be able to defreeze or melt ice which is found in the water supply, and must be able to filter undesirable materials from the water.